Figure 1.
Dose- and age-dependent mortality of chicken embryos after infection with L. corymbifera FSU 9682.
(n = 20) eggs per group, experiments were performed two (106 and 105 conidia per egg) to three (102 to 104 conidia per egg) times. Data are shown as Kaplan- Meyer curves. (A) Eggs were infected at developmental day 10 with different doses of spores as indicated. (B) Embryos were infected as indicated on developmental day (DD) 8, 10 or 12 with 103 spores per egg.
Table 1.
The twelve representative Lichtheimia and four Dichotomocladium strains used throughout this study.
Figure 2.
Virulence of Lichtheimia and Dichotomocladium species.
12 representative strains of Lichtheimia species and 4 strains of Dichotomocladium species were tested in embryonated eggs. Eggs were infected at developmental day 10 with 104 spores per egg (n = 20 per strain). Experiments were performed at least two times. Data are shown as Kaplan- Meyer curves. Survival of embryos infected with any strain was pairwise compared to survival of embryos infected with the reference strain L. corymbifera FSU 9682 using the Log rank test. *: P<0.01.
Table 2.
Virulence of 46 strains of all five Lichtheimia species in the embryonated egg.
Figure 3.
Phylogenetic tree of all used strains.
Phylogenetic tree based on ITS, 28S and 18S rDNA sequences of 46 Lichtheimia isolates from environmental (e), veterinary (v) and clinical (c) sources. Source was not known for 6 strains (u). Strains attenuated in comparison to L. corymbifera FSU 9682 (ref) are highlighted in light gray. Strains which were unable to grow at 37°C (not used for infection experiments) are highlighted in dark grey. Only bootstrap values below 0.9 are indicated.
Figure 4.
Physiological properties of the 12 representative strains of Lichtheimia and 4 strains of Dichotomocladium species.
(B to D) Growth under stress is expressed as percent growth of the same strain on medium without stressor (% growth of the control). Results were compared to the reference strain L. corymbifera FSU 9682 (statistical significance is indicated with an asterisk; two-tailed T-test, P<0.05).
Figure 5.
Physiology and virulence of Lichtheimia and Dichotomocladium strains.
Heat map generated from virulence and physiological data of 12 representative strains of Lichtheimia and 4 strains of Dichotomocladium species. Virulence is expressed as percent mortality of chicken embryos. Growth rates are expressed as percent growth of the reference strain and stress resistance as percent growth of control without stressor. The L. corymbifera FSU 9682 was used as reference strain and values obtained with this strain were set as ‘0’ by subtracting the values of the reference strain from all other values.
Figure 6.
Species designation of all ITS sequences of Lichtheimia in GenBank.
Number of sequences and percent of misidentified sequences (A). Chart pie of proportion of sequences of the different species of Lichtheimia (B).